basking lamp height

Hi I am currently upgrading my beardy from a 3foot viv to a 4 foot vivexotics vx48.I am experianced with setting up the correct heat gradients within the 3 foot vivs but was looking for some advise with regards to the inital placement of the basking lamp as i plan to fit the lamp to the top of...

Hi guys, I was just wondering how low you have the basking lamp. Or how high you have the basking stone/tile near the bulb. Just want to make sure my BTS is able to get the heat he needs. cheers Dave